Volumetric metering device for the metered delivery of granular and powdery materials particulary for machines for distributing the said materials

ABSTRACT

A volumetric metering device for the metered delivery of granular and powdery materials, particularly for machines for distributing such materials. The device comprises a housing formed in one piece of plastic material, a metering member which is supported rotatably in the housing, can be handled individually, and includes a plurality of metering wheels mounted on a shaft and clamped in a group between two flanges, a selective drive-transmission interposed between the wheels and the shaft, a scraper for cleaning the wheels in motion and anchoring the idle wheels, and a feeler device which is held at a distance from the metering member with resilient preloading.

TECHNICAL FIELD

The subject of the present invention is a metering device for themetered delivery of granular and powdery materials, particularly formachines for distributing the said materials.

TECHNOLOGICAL BACKGROUND

Volumetric metering devices are used widely in many different technicalfields in which there is a need to deliver a substantially continuousand measured flow of material over time. For example, the technicalfield of agricultural sowing machines with pneumatic seed-transportationis typical; in these machines it is known to provide a seed-loadinghopper at the base of which a metering device, generally of thevolumetric type with blades, is fitted and supplies metered quantitiesof seeds into a Venturi duct by which the seeds are admitted to anair-flow and transported to the sowing drills.

The particular and preferred application of the invention is in allcases in which it is necessary to vary the flow-rate delivered, possiblywithin a fairly large range of values.

Typical metering devices formed in accordance with the prior art aredescribed, for example, in EP 0702890, EP0606541, EP 0471155, and U.S.Pat. No. 6,138,591.

Conventional metering devices normally comprise a box-like structure inwhich a bladed metering member is supported rotatably and cooperateswith a flow-restricting device for regulating the flow-rate delivered.In one example, the restricting device comprises a jacket movableaxially in adjustable manner relative to the rotor of the distributor soas to cover a portion of the set of blades in order to reduce theoverall capacity of the cells available. Alternatively, the rate ofrotation of the metering member may be varied, or the capacity of thecells may be varied.

A first problem resulting from the known structure of conventionaldistributors is that they do not permit large adjustments of flow-ratewhilst maintaining constant regulation of the metering for eachadjustment. In fact there are critical speeds of the metering memberbeyond which its reliability is reduced.

A second problem typical of known structures is that they comprise aplurality of parts which have to be assembled by means of connections,screws, flanges etc. This philosophy is rather unsuitable foragricultural machines for which many adjustments have to be performed inthe field and the consequent need to remove various parts may lead totheir loss, making reassembly impossible.

A further problem characteristic of metering devices is that they aresubject to irremediable damage, or at least to blockage of the meteringmember, when foreign bodies of considerable size reach its rotor. In theabsence of a timely indication of this situation, particularly duringsowing, it is possible, completely unwittingly, to sow whole fieldsunevenly or not at all.

DESCRIPTION OF THE INVENTION

These problems and yet others which will become clearer from thefollowing description are addressed and solved by the invention by meansof a metering device formed in accordance with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics and the advantages of the invention will becomeclearer from the detailed description of a preferred but not exclusiveembodiment described by way of non-limiting example, with reference tothe appended drawings, in which:

FIG. 1 is a schematic view showing, in section, the basic components ofa machine for distributing granular materials,

FIG. 2 is an exploded, perspective view of a delivery device formed inaccordance with the present invention,

FIG. 3 and FIG. 4 are exploded views of respective variants of a detailof the device of FIG. 2,

FIGS. 5, 6 and 7 are perspective views of the device of FIG. 2 in theassembled condition, taken from different angles,

FIGS. 8 and 9 are perspective views of the device of FIG. 2 in an onlypartially assembled condition, taken from different angles,

FIG. 10 is a perspective view of a detail of the device of FIG. 2, on anenlarged scale, and

FIG. 11 is a side view of a further detail of the device of FIG. 2.

PREFERRED EMBODIMENT OF THE INVENTION

With reference to FIG. 1, a machine for distributing granular materials,usable both for sowing seeds and for spreading manure, disinfectantsetc., is generally indicated 1. The machine 1 comprises, basically, oneor more hoppers 2 for holding the material to be spread, a blower 3which delivers an air-flow under pressure to an air injector 4, ametering device 5 which supplies metered quantities of the materialpresent in the hopper into the air-flow generated by the blower 3, and adistributor 6 which distributes the mixed flow of air and materialtransported thereby towards distribution ducts 7.

The metering device 5 can advantageously be constructed in accordancewith one or more of the teachings of the present invention and is shownin detail in FIG. 2 and the subsequent figures.

The device comprises a housing 10 which, by virtue of the provisions ofthe invention, can advantageously be constructed in a single piece bymoulding of plastics material. The housing 10 comprises a first, upperopening 11 which is open towards the hopper 2, a second, rear opening12, closed in an openable manner by a removable door 14, and an opposed,third opening 15 which admits the granular material to the region of theair injector. The housing is closed at the bottom by a feeler member 16which will be described further below.

The housing 10 further comprises opposed side walls 17 having twocircular and coaxial through-holes 18. The holes serve for housing ametering member, generally indicated 20, in the housing 10.

The metering member 20 comprises a shaft 21 of polygonal, preferablysquare, cross-section, having, at one end, a joint 22 by means of whichit can be coupled for rotation with a drive shaft (not shown) and, atthe other, opposite end, a threaded shank 23 onto which a hand wheel 24is screwed with the interposition of a washer 25. The assembly serves toclamp to the shaft 21 a plurality of metering wheels 26, included in agroup between two flanges 27 and intercalated with discs 28.

The flanges 27 are identical to one another and each has two externaltracks 29 a, 29 b which serve to support the metering member in thehousing 10 rotatably but with axial restraint. Support is achieved bymeans of three or more bearings 30 a, 30 b, 30 c, the outer portions ofwhich are in rolling contact with one or other of the tracks 29 a, 29 b.The axial restraint is not actually necessary for the operation of thedevice since the shaft 21 is itself fixed axially relative to thehousing as a result of its connection to the drive shaft by means of thejoint 22. However, to prevent the metering member 20 from accidentallycoming out of the housing 10 when the device is released from the driveshaft, the tracks 29 a, 29 b have different diameters (the track 29 a,closer to the side wall of the housing, has a larger diameter) and onebearing 30 a is fixed to the housing 10 removably by means of the handwheel 32 and is engaged on the track 29 b so that the shoulder existingbetween the two tracks performs the desired axial restraint. In order toremove the metering member from the housing, the hand wheel 32 isslackened, removing the bearing 30 a and with it the axial restraintpreventing the metering member from slipping out.

Both of the flanges, or at least one of them, may have a ring of axialseats 33 for cores (for examples, screws) cooperating with a proximitydetector (not shown) in order to measure the rate of rotation of themetering member 20.

Each metering wheel 26 is moulded of plastics material and comprises aplurality of blades 36 which extend radially from a hub 37 having anaxial hole 37 a with a channelled profile in which the channels have aprofile which can be coupled with the shaft 21 and the number ofchannels is a multiple of the number of sides of the shaft so as topermit different angular positionings of the wheels 26 on the shaft 21.The wheels can thus be mounted in a manner such that they are offsetangularly relative to one another, improving the uniformity of theoutput.

Both to take account of this angular offset and to strengthen the bladesat their free ends, axial appendages 38 are provided thereon and arehoused in corresponding holes 39 in the discs 28. The discs 28 havecircular holes and are not otherwise driven by the shaft 21.

The wheels 26 are interchangeable with second wheels 26 a of differentvolumetric capacity or even with third wheels 40 of low volumetriccapacity, which can also be mounted on the shaft 21 with theinterposition of a release mechanism 41 (see FIGS. 3 and 4). One or moreof the third wheels 40 can thus be disconnected from the drive of theshaft simply by being turned through 180°. In one direction, themechanism 41 in fact brings about driving of the wheel 40 together withthe shaft 21, whereas in the opposite direction, the mechanism 41 isdisengaged from the shaft 21, rendering the wheel 40 idle. Moreover, forintermediate capacities, the first and second wheels 26, 26 a, may becombined in the metering member 20, by being arranged alternately in thegroup of wheels.

A particular problem which is solved by the invention lies in the factthat some minute seeds with a high oil content (typically rape seeds)tend to release greasy substances into the cells of the metering wheels(and into the metering device in general), changing its capacity (to theextent of reducing it to zero). This specific problem has been solved bythe invention by means of a special scraper device 50 which is mounteddownstream of the region in which the seeds fall. The scraper 50comprises a shaft 50 a on which bow-shaped metal scraper members 51, forexample, of harmonic steel, are mounted; the number of scraper members51 corresponds to the number of wheels 40. Each scraper member has acrosspiece 52 which can follow the profiles of the cells, deforming thecorresponding bow resiliently whilst the wheel 40 rotates. The shaft 50a is in turn rotatable on the housing between two positions in which thescraper members are disengaged from the wheels or, conversely, areengaged in contact therewith, respectively. Oily residues which tend tostick to the seeds and to the ever-present dust, are thus removed andfall into the pneumatic seed-conveyor duct in order to be removed fromthe device 5.

Again, with oily seeds, in spite of the provision of release mechanisms,one or more of the wheels which are intended to be rendered idle bybeing turned around on the shaft 21 may nevertheless be rotated as aresult of the internal friction which is increased by the presence ofresidues of dirt. To prevent this occurring, the wheels 40 according tothe present invention have, in one or more of the cells formed in theirsurfaces between adjacent blades, respective tooth-like formations 54which, in one direction of rotation, offer the crosspieces 52 of thescraper members an inclined rear face 55 on which the crosspiece 52 doesnot grip whereas, in the other direction of rotation, they offer thecrosspiece 42 a substantially radial leading face with which thecrosspiece 52 engages, preventing further driving of the wheel 40. Anexample of this function relates to the central wheel of FIG. 10.

The ability to release the scrapers from the wheels 40 when they are notrequired considerably reduces wear of the scrapers, maintaining theireffective life.

A further advantageous aspect of the invention lies in the structure andfunctional capacity of the feeler member 16. In known solutions, thismember is generally constituted by a pivoting scraper blade providedwith a resilient rubber lip. The main disadvantages resulting from thisstructure are connected with the fact that, with variations in the rateof rotation of the metering member, the rubber lip deforms, varying theflow-rate of the device in a non-predetermined manner. Moreover, thepassage of any foreign body (a stone or the like) can block its pivotingin the open position, with a consequent unexpected change in themetering.

The feeler member 16 according to the invention comprises a plurality ofindividual feeler elements 60, each having a first end engaged on ashaft 61 and each carrying, at its opposite end, a fork 62 which housesa further shaft 63 with predetermined clearance. The fork prong 66facing the metering member 20 carries a resilient lip 67. Both of theshafts 61, 63 are supported between the side walls 17 of the housing 10.

The feeler elements 60 are spaced apart by fixed plate-shaped separators68, which are also articulated on the shaft 61 at one end and engage theshaft 63 with their opposite ends, but without the ability to pivotabout the shafts.

In the region of the fork 62, there are resilient preloading means, eachincluding a helical spring 64 and a respective stay 65, which urge therespective feeler element 60 towards the corresponding metering wheel.However, the feeler element is kept spaced therefrom by the interactionof the corresponding prong of the fork 62 with the shaft 63.Alternatively, similar resilient preloading means are arranged to beactive at the opposite end of each feeler element. It is thus possibleto apply to the elements 60 a predetermined resilient preloading,preferably of the order of about 1.5 kg, without this leading tocompression of the lip 67 against the metering member which, inconventional systems, is a potential cause of rupture of the seedsdistributed. On the other hand, the feeler elements can performoscillations about the shaft 61 which are limited by the other prong ofthe fork 62 so as to prevent the feeler member from opening completely,significantly altering the distribution parameters. This precaution isaugmented by the provision of individual and independent feeler elementsfor each wheel.

With these means for limiting the pivoting of the feeler member,breakages f the feeler elements could occur should foreign bodies ofdimensions larger than he maximum opening between the feeler elementsand the respective wheels pass through the metering member. To preventthis, according to a further characteristic of the invention, eachseparator 68 is arranged to have a nib 69 of a shape and size such as toalter the angle of introduction between the feelers and the meteringmember 20 so that foreign bodies arriving in the introduction openingbetween the feelers and the metering body are “rejected” by virtue ofthe increased amplitude of the angle of introduction as defined aboveand are prevented from entering the introduction opening. By way ofindication, the angle of introduction as varied by the provision of thenibs 68 is about 80°.

According to a further characteristic of the invention, flow separatormeans 70 may be arranged in the region of the opening 15 for admittingthe granular material into the air-flow which is responsible for itstransportation. These separator means 70 are of the type comprising afixed plate supported, by means of notches 71, on shafts 72, 73extending between the side walls 17 of the housing 10. The shaft 72 alsoserves to support respective surfaces for collecting the seed andsending it to the air-injection duct 4.

On the side facing the metering member, the separator plate 70 has anarcuate profile 74 complementary with the outer surface of a toothlesswheel 75 which is fitted centrally between the metering wheels. It isthus possible, with a single metering device, to supply two distributorsand respective blowers separately, in fact doubling the capacity of thedistributing machine.

According to an additional characteristic of the invention, secondseparator means 76 may be disposed in the housing, upstream of themetering member 20, so as to separate, not only at the output but alsoat the input, products which may optionally be different and which canbe metered by a single metering device. The second separator means 76comprise a fixed plate, also provided with an arcuate profile 77complementary with the surface of the toothless wheel 75, and havingteeth 78 for engagement on a plate 79 which is equipped with two doors80 and can replace the door 14 when this arrangement is selected.Amongst the advantages conferred by this technical solution is the factthat it is possible to distribute different products through theright-hand and left-hand sides of the same metering device. For example,it is possible to construct sowing machines with double seed-loadinghoppers and a single metering device suitable, for example, for sowingalternating bands of male and female plants for the production ofselected hybrids. That is, it is possible to distribute differentproducts simultaneously, optionally with different metering, adjustablein dependence on the type of metering wheels used for the right-hand andleft-hand sides.

Finally, a stirrer 81 is provided, supported rotatably between the sidewalls 17 of the housing 10 and rotated by the joint 22, by means of abelt transmission 82.

The metering device of the present invention thus achieves the objectsindicated, at the same time offering many advantages over the prior art,amongst which is greater ease of handling during operations to assembleand dismantle the individual components.

1. A volumetric metering device for the metered delivery of granular andpowdery materials, particularly for machines for distributing suchmaterials, comprising a housing formed in a single piece and a meteringmember supported rotatably in the housing.
 2. The device according toclaim 1 in which the housing is molded of plastic material.
 3. Avolumetric metering device for the metered delivery of granular andpowdery materials, particularly for machines for distributing suchmaterials, comprising: a housing having juxtaposed openings each with adimension; and a metering member having at least one metering wheelclamped between a pair of flanges, the dimension of at least onejuxtaposed opening of the housing allowing the metering member, completewith the at least one metering wheel and the flanges, to pass from andtowards the housing, at least one of the flanges being arranged to closethe respective opening when the metering member is fitted in theoperative position in the housing, and providing rotatable support ofthe metering member in the housing.
 4. The device according to claim 3in which both of the openings have dimensions such as to allow themetering member, complete with the at least one wheel and the flanges,to pass from and towards the housing, both of the flanges being arrangedto close the respective openings when the metering member is fitted inthe operative position in the housing, and providing rotatable supportof the metering member in the housing.
 5. The device according to claim3 in which the flanges carry peripherally at least two rolling tracksfor at least one bearing or wheel, a shoulder being defined between thetracks, and the at least one bearing or wheel being restrained on thehousing for the rotatable support of the metering member and for theaxial restraint thereof via the shoulder.
 6. The device according toclaim 5 in which at least one of the bearings or wheels is removablefrom the housing to allow the metering member to be moved away from andtowards the housing.
 7. A volumetric metering device for the metereddelivery of granular and powdery materials, particularly for machinesfor distributing such materials, comprising a metering member includinga plurality of metering wheels which are structurally independent of oneanother and are interposed in a group between a pair of flanges, and ashaft acting as a tie between the flanges in order to clamp in a groupthe flanges and the metering wheels interposed between them, toconstitute a unit which can be handled individually.
 8. The deviceaccording to claim 7 in which the shaft comprises, at one of its ends, ajoint for connection to a drive shaft.
 9. The device according to claim8 in which the shaft has means for clamping the group of flanges andwheels at the end remote from the joint, the joint acting as an abutmentshoulder for the clamping.
 10. The device according to claim 7, in whichthe shaft has a polygonal cross-section.
 11. The device according toclaim 10 in which each of the metering wheels has a hub having a hole ofpolygonal cross-section configured to be coupled with the polygonalcross-section of the shaft.
 12. The device according to claim 11 inwhich the holes in the hubs of the metering wheels have channelledprofiles configured for coupling with the profile of the shaft and thenumber of channels is a multiple of the number of sides of the shaft soas to permit various angular positionings of the metering wheels on theshaft.
 13. A volumetric metering device for the metered delivery ofgranular and powdery materials, particularly for machines fordistributing such materials, comprising a metering member carrying aplurality of metering wheels having blades and clamped together in agroup, the blades having appendages restraining the blades of one wheelon the blades of the adjacent wheel.
 14. The device according to claim13 further comprising a disc having holes for the appendages, the discbeing interposed between adjacent metering wheels constituting aninterconnection element between the blades of adjacent wheels.
 15. Thedevice according to claim 14 in which the disc has seats for theappendages, the seats being offset relative to one another to permit anangularly offset interconnection of the sets of blades of adjacentwheels.
 16. The device according to claim 13 in which the meteringwheels can be interchanged, combined, or both interchanged and combinedwith wheels of different dimensions.
 17. A volumetric metering devicefor the metered delivery of granular and powdery materials, particularlyfor machines for distributing such materials, comprising a meteringmember having metering wheels clamped in a group and keyed to a commondrive-transmission shaft, and selective drive-transmission meansinterposed between the wheels and the shaft in order to exclude thewheels from driving by the shaft or, conversely, to connect the wheelsfor driving by the shaft.
 18. The device according to claim 17 in whichthe metering wheels are mounted reversibly on the shaft and theselective drive-transmission means comprises a release mechanism whichbrings about the driving connection between wheels and shaft in a firstmounting condition and disconnection between wheels and shaft in asecond mounting condition, in which the metering wheels are turnedthrough 180° relative to the first mounting condition.
 19. The deviceaccording to claim 18 further comprising a scraper active on the wheelsindividually to remove deposits therefrom.
 20. The device according toclaim 19 in which the scraper comprises a plurality of resilient bowseach active on the respective wheel individually.
 21. The deviceaccording to claim 19 in which the scraper is movable relative to themetering member between an operative position in which the scraper isactive on the wheels and an inoperative position in which the scraper isspaced therefrom.
 22. The device according to claim 19 in which thescraper and the metering wheels comprise a mutual engagement means forrestraining the metering wheels in a stationary position when they areexcluded from driving by the shaft.
 23. The device according to claim 22in which the mutual engagement means comprises a crosspiece on eachscraper and at least one tooth-like element on each metering wheel, thetooth-like element defining a leading face engaging the crosspiece whenthe metering wheel is oriented in the second mounting condition anddefining an inclined rear face which slides relative to the crosspiecewhen the metering wheel is oriented in the first mounting condition. 24.A volumetric metering device for the metered delivery of granular andpowdery materials, particularly for machines for distributing suchmaterials, comprising: a housing; a metering member supported rotatablyin the housing; a feeler device mounted in the housing and active in themanner of a scraper blade with a lip thereof operative on the meteringmember; restraining means active on the feeler device for maintaining apredetermined distance between the feeler device and the meteringmember; and a resilient preloading mechanism active on the feeler devicein order to press its operative lip towards the metering member withpredetermined preloading.
 25. The device according to claim 24 in whichthe feeler device comprises a plurality of feeler elements activeindividually and independently on respective corresponding meteringwheels of the metering member.
 26. The device according to claim 25 inwhich the feeler elements are articulated pivotably by their respectiveends remote from the operative lip on a shaft fixed to the housing, andmeans are provided for limiting their pivoting relative to the shaft.27. The device according to claim 26 in which the means for limitingpivoting comprises, at the end corresponding to the operative lip, afork-shaped element between the prongs of which a second shaft is housedwith predetermined clearance.
 28. A volumetric metering device for themetered delivery of granular and powdery materials, particularly formachines for distributing such materials, comprising a housing; ametering member supported rotatably in the housing; a feeler devicemounted in the housing and active in the manner of a scraper blade witha lip thereof operative on the metering member; and means for alteringlocally the angle of introduction between the feeler device and themetering member, the means being associated with the feeler device,immediately upstream of the operative lip.
 29. The device according toclaim 28 in which the feeler device comprises a plurality of feelerelements active individually and independently on respectivecorresponding metering wheels and the means for altering the angle ofintroduction comprises a plurality of separators interposed between thefeeler elements and each having a nib projecting towards the meteringdevice.
 30. The device according to claim 29 in which the housing has aninput and a region including an output opening and the device furthercomprises first flow-separator means disposed in the region of theoutput opening of the housing.
 31. The device according to claim 30 inwhich the first separator means comprises a fixed plate supported, bynotches, on shafts extending between side walls defined in the housing,the plate having, on the side facing the metering member, an arcuateprofile complementary with the outer surface of a toothless wheel whichis fitted centrally between the metering wheels.
 32. The deviceaccording to claim 31 further comprising second separator means aredisposed in the housing upstream of the metering member so as toseparate products, which may optionally be different, at the input. 33.The device according to claim 32 in which the second separator meanscomprises a fixed plate having an arcuate profile complementary with thesurface of the toothless wheel.
 34. The device according to claim 3 inwhich the at least one metering wheel can be interchanged, combined, orboth interchanged and combined with wheels of different dimensions. 35.The device according to claim 7 in which the metering wheels can beinterchanged, combined, or both interchanged and combined with wheels ofdifferent dimensions.
 36. The device according to claim 1 in which thehousing has an input and a region including an output opening and thedevice further comprises first flow-separator means disposed in theregion of the output opening of the housing.
 37. The device according toclaim 36 in which the first separator means comprises a fixed platesupported, by notches, on shafts extending between side walls defined inthe housing, the plate having, on the side facing the metering member,an arcuate profile complementary with the outer surface of a toothlesswheel which is fitted centrally between metering wheels of the meteringmember.
 38. The device according to claim 37 further comprising secondseparator means disposed in the housing upstream of the metering memberso as to separate products, which may optionally be different, at theinput.
 39. The device according to claim 38 in which the secondseparator means comprises a fixed plate having an arcuate profilecomplementary with the surface of the toothless wheel.
 40. The deviceaccording to claim 3 in which the housing has an input and a regionincluding an output opening and the device further comprises firstflow-separator means disposed in the region of the output opening of thehousing.
 41. The device according to claim 40 in which the firstseparator means comprises a fixed plate supported, by notches, on shaftsextending between side walls defined in the housing, the plate having,on the side facing the metering member, an arcuate profile complementarywith the outer surface of a toothless wheel which is fitted centrallybetween metering wheels of the metering member.
 42. The device accordingto claim 41 further comprising second separator means disposed in thehousing upstream of the metering member so as to separate products,which may optionally be different, at the input.
 43. The deviceaccording to claim 42 in which the second separator means comprises afixed plate having an arcuate profile complementary with the surface ofthe toothless wheel.
 44. The device according to claim 7 furthercomprising a housing having an input and a region including an outputopening, and first flow-separator means disposed in the region of theoutput opening of the housing.
 45. The device according to claim 44 inwhich the first separator means comprises a fixed plate supported, bynotches, on shafts extending between side walls defined in the housing,the plate having, on the side facing the metering member, an arcuateprofile complementary with the outer surface of a toothless wheel whichis fitted centrally between the metering wheels of the metering member.46. The device according to claim 45 further comprising second separatormeans disposed in the housing upstream of the metering member so as toseparate products, which may optionally be different, at the input. 47.The device according to claim 46 in which the second separator meanscomprises a fixed plate having an arcuate profile complementary with thesurface of the toothless wheel.
 48. The device according to claim 13further comprising a housing having an input and a region including anoutput opening, and first flow-separator means disposed in the region ofthe output opening of the housing.
 49. The device according to claim 48in which the first separator means comprises a fixed plate supported, bynotches, on shafts extending between side walls defined in the housing,the plate having, on the side facing the metering member, an arcuateprofile complementary with the outer surface of a toothless wheel whichis fitted centrally between the metering wheels of the metering member.50. The device according to claim 49 further comprising second separatormeans disposed in the housing upstream of the metering member so as toseparate products, which may optionally be different, at the input. 51.The device according to claim 50 in which the second separator meanscomprises a fixed plate having an arcuate profile complementary with thesurface of the toothless wheel.
 52. The device according to claim 17further comprising a housing having an input and a region including anoutput opening, and first flow-separator means disposed in the region ofthe output opening of the housing.
 53. The device according to claim 52in which the first separator means comprises a fixed plate supported, bynotches, on shafts extending between side walls defined in the housing,the plate having, on the side facing the metering member, an arcuateprofile complementary with the outer surface of a toothless wheel whichis fitted centrally between the metering wheels of the metering member.54. The device according to claim 53 further comprising second separatormeans disposed in the housing upstream of the metering member so as toseparate products, which may optionally be different, at the input. 55.The device according to claim 54 in which the second separator meanscomprises a fixed plate having an arcuate profile complementary with thesurface of the toothless wheel.
 56. The device according to claim 24 inwhich the housing has an input and a region including an output openingand the device further comprises first flow-separator means disposed inthe region of the output opening of the housing.
 57. The deviceaccording to claim 56 in which the first separator means comprises afixed plate supported, by notches, on shafts extending between sidewalls defined in the housing, the plate having, on the side facing themetering member, an arcuate profile complementary with the outer surfaceof a toothless wheel which is fitted centrally between metering wheelsof the metering member.
 58. The device according to claim 57 furthercomprising second separator means disposed in the housing upstream ofthe metering member so as to separate products, which may optionally bedifferent, at the input.
 59. The device according to claim 58 in whichthe second separator means comprises a fixed plate having an arcuateprofile complementary with the surface of the toothless wheel.